PLAINFIELD, Ind. -- Car by car, truck by truck, the dozens of people involved in the 35-car pileup on an Indiana highway Thursday are stuck -- and will be for a long time.

As temperatures plummet toward the single digits Thursday night, State Police and local officers say they are moving from the back of a long line of cars toward the center point of the crash on Interstate 70, stopping at each to get license information, plate numbers and other information from each driver at the scene.

The massive crash on I-70 west of Indianapolis injured at least seven motorists and resulted in a major shutdown of the highway between Plainfield and Monrovia, Ind.

State Police said the chain-reaction crash took place shortly after 2 p.m. near an overpass at Hendricks County Road 275 East. Underneath the overpass, there are several semi's piled up which presents a challenge for tow-truck operators.

First Sgt. Dave Bursten said there were at least seven people injured -- a few of them serious.

"Most are just bumps and bruises but a couple of them are believed to be serious," said Bursten. "At this time we don't believe any of them are life threatening."

So far, police have counted 20 semi trailers and at least 15 passenger vehicles involved in the crash.

The highway is littered with crumpled cars and motorists who are stuck on both sides of the highway.

Complicating matters further was the fact that a few of the semi's were hauling fuel and anti-freeze and some of that spilled onto the highway as a result of the crash.

The hazardous materials team was called in to clean that up.

Troy Brindley of Monrovia is one of those waiting for the wreckage to be cleared.

His vehicle is not far from the overpass at Hendricks County Road 725 East, which means he is close to the center of the crash scene and knows he has a 6-to-8 hour wait before he is permitted to leave.

"He is not hurt but he can't get out yet," said his wife, Rebecca, as she stood on the overpass, overlooking the scene. "As soon as he got stopped, he called and said, 'I'm fine, I'm fine. I kinda slid into the back of a semi.' "

Brindley said her husband reported that just before the crash, snow was falling heavily and he was moving along at 30 miles per hour with his emergency blinkers going.

State Police Sgt. Joe Watts said dealing with so many vehicles is not going to be an easy task.

Vehicles on the eastbound side of the road -- which were not involved in any crash -- were slowly being let out of the mess through a single lane of traffic moving toward the Plainfield exit. Vehicles on the westbound side of the road, were eventually permitted to make their way across the median onto the eastbound lanes to go back toward Plainfield.

Officials at Indianapolis International Airport, which sits just east of the accident scene, say they have been getting calls from nervous passengers hoping to make their flights.

"We have been getting inquires from passengers who have been rerouted," said Carlo Bertolini, airport spokesman, who added they've placed an alert on their website.

"I can tell you that passengers have called advising they were not permitted to access I-70 from I-465 near the airport, meaning they would have to use Sam Jones or Washington street for alternate routes to (the airport)."